Resist-as-Needed ADL Training With SPINDLE for Patients With Tremor.

Individuals with neurological disorders often exhibit altered manual dexterity and muscle weakness in their upper limbs. These motor impairments with tremor lead to severe difficulties in performing Activities of Daily Living (ADL). There is a critical need for ADL-focused robotic training that improves individual's strength when engaging with dexterous ADL tasks. This research introduces a new approach to training ADLs by employing a novel robotic rehabilitation system, Spherical Parallel INstrument for Daily Living Emulation (SPINDLE), which incorporates Virtual Reality (VR) to simulate ADL tasks. The study results present the feasibility of training individuals with movements similar to ADLs while interacting with the SPINDLE. A new game-based robotic training paradigm is suggested to perform ADL tasks at various intensity levels of resistance as needed. The proposed system can facilitate the training of various ADLs requiring 3-dimensional rotational movements by providing optimal resistance and visual feedback. We envision this system can be utilized as a table-top home device by restoring the impaired motor function of individuals with tremor and muscle weakness, guiding to improved ADL performance and quality of life.

Multidisciplinary inpatient rehabilitation for Functional Movement Disorders: A prospective study with long term follow up.

INTRODUCTION: Functional Movement Disorders (FMDs) are challenging to treat. We assessed the effect of multidisciplinary inpatient rehabilitation, involving motor retraining, psychotherapy and psychotropic medication on FMD patient function and maintenance of improvement after one year. METHODS: FMD patients in a movement disorders clinic were referred for inpatient rehabilitation. Baseline, discharge and one year follow-up measures included: Clinical Global Impression (CGI-severity, CGI-change); Depression and Somatic Symptom Scale (DSSS); Generalized Anxiety Disorder-7 (GAD-7); Patient Health Questionnaire-9 (PHQ-9); Post-traumatic stress disorder check-list for DSM-5 (PCL-5). Outcomes were analyzed with non-parametric models. RESULTS: Seventeen patients completed rehabilitation. Thirteen completed one-year follow-up. Median CGI-severity was "markedly ill." At discharge, movement disorder improved in 93% (median CGI-change = 2, "much improved") as assessed by neurologist and patient. Psychiatrist ratings showed improvement among 86.7%; physiatrist and psychologist ratings were 66.7% and 53.3%, respectively. Symptoms improved on DSSS (Wilcoxon Z = -2.914, p ≤ 0.004); GAD-7 (Z = -3.045, p ≤ 0.002); PHQ-9 (Z = -3.415, p ≤ 0.01) but not PCL-5 (Z = -1.506, p = 0.132). At 1 year, 54% maintained at least minimal improvement by neurologist rating and 77% by patient rating (median CGI-change = 3, "minimally improved"). Improvement was not maintained for DSSS (Wilcoxon Z = -0.385. p = 0.701), GAD-7 (Z = -0.943, p = 0.357) or PHQ-9 (Z = -0.55, p = 0.582). CONCLUSIONS: Multidisciplinary inpatient rehabilitation improved FMD patient function, depression, anxiety and somatic symptoms. One-year follow-up demonstrated minimal sustained improvement and worsening psychopathology, reflecting chronic debility despite initial rehabilitative success.

Localization of motor and verbal fluency effects in subthalamic DBS for Parkinson's disease.

INTRODUCTION: Subthalamic nucleus deep brain stimulation (STN DBS) improves cardinal motor symptoms of Parkinson's disease (PD) but can worsen verbal fluency (VF). An optimal site of stimulation for overall motor improvement has been previously identified using an atlas-independent, fully individualized, field-modeling approach. This study examines if cardinal motor components (bradykinesia, tremor, and rigidity) share this identified optimal improvement site and if there is co-localization with a site that worsens VF. METHODS: An atlas-independent, field-modeling approach was used to identify sites of maximal STN DBS effect on overall and cardinal motor symptoms and VF in 60 patients. Anatomic coordinates were referenced to the STN midpoint. Symptom severity was assessed with the MDS-UPDRS part III and established VF scales. RESULTS: Sites for improved bradykinesia and rigidity co-localized with each other and the overall part III site (0.09 mm lateral, 0.93 mm posterior, 1.75 mm dorsal). The optimal site for tremor was posterior to this site (0.10 mm lateral, 1.40 mm posterior, 1.93 mm dorsal). Semantic and phonemic VF sites were indistinguishable and co-localized medial to the motor sites (0.32 mm medial, 1.18 mm posterior, 1.74 mm dorsal). CONCLUSION: This study identifies statistically distinct, maximally effective stimulation sites for tremor improvement, VF worsening, and overall and other cardinal motor improvements in STN DBS. Current electrode sizes and voltage settings stimulate all of these sites simultaneously. However, future targeted lead placement and focused directional stimulation may avoid VF worsening while maintaining motor improvements in STN DBS.

Design of a lightweight passive orthosis for tremor suppression.

BACKGROUND: Tremor is the most common movement disorder with the highest prevalence in the upper limbs. The mechanical suppression of involuntary movements is an alternative and additional treatment to medication or surgery. Here we present a new, soft, lightweight, task asjustable and passive orthosis for tremor suppression. METHODS: A new concept of a manual, textile-based, passive orthosis was designed with an integrated, task adjustable, air-filled structure, which can easily be inflated or deflated on-demand for a certain daily activity. The air-filled structure is placed on the dorsal side of the wrist and gets bent and compressed by movements when inflated. In a constant volume air-filled structure, air pressure increases while it is inflating, creating a counterforce to the compression caused by bending. We characterised the air-filled structure stiffness by measuring the reaction torque as a function of the angle of deflection on a test bench. Furthermore, we evaluated the efficacy of the developed passive soft orthosis by analysing the suppression of involuntary movements in the wrist of a tremor-affected patient during different activities of daily living (i.e. by calculating the power spectral densities of acceleration). RESULTS: By putting special emphasis on the comfort and wearability of the orthosis, we achieved a lightweight design (33 g). The measurements of the angular deflection and resulting reaction torques show non-linear, hysteretic, behaviour, as well as linear behaviour with a coefficient of determination (R2) between 0.95 and 0.99. Furthermore, we demonstrated that the soft orthosis significantly reduces tremor power for daily living activities, such as drinking from a cup, pouring water and drawing a spiral, by 74 to 82% (p = 0.03); confirmed by subjective tremor-reducing perception by the patient. CONCLUSION: The orthosis we developed is a lightweight and unobtrusive assistive technology, which suppresses involuntary movements and shows high wearability properties, with the potential to be comfortable. This air-structure technology could also be applied to other movement disorders, like spasticity, or even be integrated into future exoskeletons and exosuits for the implementation of variable stiffness in the systems.

Effect of eccentric-based rehabilitation on hand tremor intensity in Parkinson disease.

BACKGROUND AND PURPOSE: Hand tremor is a disturbing yet sometimes resistant symptom in persons with Parkinson disease (PD). Although many exercise regimens for these people have gained attention in recent years, the effect of resistance training and especially eccentric training on parkinsonian tremor is still uncertain. This study was conducted to investigate the precise effect of upper limb eccentric training on hand tremor in PD. METHODS: In this randomized controlled trial, a consecutive sample of 21 persons with PD recruited from general hospitals went through 6 weeks of upper limb pure eccentric training as the intervention group (n = 11) or no additional exercise during this period as the control group (n = 10). Resting and postural tremor amplitudes were measured with the cellphone-based accelerometer. RESULTS: Comparing hand tremor amplitudes before and after the trial showed a significant reduction in resting tremor amplitude in the intervention group after exercise sessions (p < 0.05) while detecting no changes in the control group during 6 weeks of study. Meanwhile, postural tremor amplitude remained unchanged in both groups.

Comprehensive, blinded assessment of balance in orthostatic tremor.

INTRODUCTION: Orthostatic Tremor (OT) is a movement disorder characterized by a sensation of unsteadiness and tremors in the 13-18 Hz range present upon standing. The pathophysiology of OT is not well understood but there is a relationship between the sensation of instability and leg tremors. Despite the sensation of unsteadiness, OT patients do not fall often and balance in OT has not been formally assessed. We present a prospective blinded study comparing balance assessment in patients with OT versus healthy controls. METHODS: We prospectively enrolled 34 surface Electromyography (EMG)-confirmed primary OT subjects and 21 healthy controls. Participants underwent evaluations of balance by blinded physical therapists (PT) with standardized, validated, commonly used balance scales and tasks. RESULTS: OT subjects were mostly female (30/34, 88%) and controls were majority males (13/20, 65%). The average age of OT subjects was 68.5 years (range 54-87) and for controls was 69.4 (range 32-86). The average duration of OT symptoms was 18 years. OT subjects did significantly worse on all the balance scales and on most balance tasks including Berg Balance Scale, Functional Gait Assessment, Dynamic Gait Index, Unipedal Stance Test, Functional Reach Test and pull test. Gait speed and five times sit to stand were normal in OT. CONCLUSIONS: Common validated balance scales are significantly abnormal in primary OT. Despite the objective finding of impaired balance, OT patients do not commonly have falls. The reported sensation of unsteadiness in this patient population seems to be out of proportion to the number of actual falls. Further studies are needed to determine which components of commonly used balance scales are affected by a sensation of unsteadiness and fear of falling.

Degeneration of paramedian nuclei in the thalamus induces Holmes tremor in a case of artery of Percheron infarction.

RATIONALE: Holmes' tremor is an uncommon neurologic disorder following brain insults, and its pathogenesis is undefined. The interruption of the dento-rubro-thalamic tract and secondary deterioration of the nigrostriatal pathway are both required to initiate Holmes' tremor. We used nuclear medicine imaging tools to analyze a patient with concurrent infarction in different zones of each side of the thalamus. Finding whether the paramedian nuclear groups of the thalamus were injured was a decisive element for developing Holmes' tremor. PATIENT CONCERNS: A 36-year-old woman was admitted to our department due to a bilateral paramedian thalamic infarction. Seven months after the stroke, a unilaterally involuntary trembling with irregularly wavering motions occurring in both her left hand and forearm. DIAGNOSIS: Based on the distinct features of the unilateral coarse tremor and the locations of the lesions on the magnetic resonance imaging (MRI), the patient was diagnosed with bilateral paramedian thalamic infarction complicated with a unilateral Holmes' tremor. INTERVENTIONS: The patient refused our recommendation of pharmacological treatment with levodopa and other dopamine agonists based on personal reasons and was only willing to accept physical and occupational training programs at our outpatient clinic. OUTCOMES: We utilized serial anatomic and functional neuroimaging of the brain to survey the neurologic deficit. A brain magnetic resonance imaging showed unequal recovery on each side of the thalamus. The residual lesion appeared larger in the right-side thalamus and had gathered in the paramedian area. A brain perfusion single-photon emission computed tomography (SPECT) revealed that the post-stroke hypometabolic changes were not only in the right-side thalamus but also in the right basal ganglion, which was anatomically intact. Furthermore, the brain Technetium-99m-labeled tropanes as a dopamine transporter imaging agents scan ( Tc-TRODAT-1) displayed a secondary reduction of dopamine transporters in the right nigrostriatal pathway which had resulted from the damage on the paramedian nuclear groups of the right-side thalamus. LESSONS: Based on the functional images, we illustrated that a retrograde degeneration originating from the thalamic paramedian nuclear groups, and extending forward along the direct innervating fibers of the mesothalamic pathway, played an essential role towards initiating Holmes' tremor.

Cognitive Stress Reduces the Effect of Levodopa on Parkinson's Resting Tremor.

AIMS: Resting tremor in Parkinson's disease (PD) increases markedly during cognitive stress. Dopamine depletion in the basal ganglia is involved in the pathophysiology of resting tremor, but it is unclear whether this contribution is altered under cognitive stress. We test the hypothesis that cognitive stress modulates the levodopa effect on resting tremor. METHODS: Tremulous PD patients (n = 69) were measured in two treatment conditions (OFF vs. ON levodopa) and in two behavioral contexts (rest vs. cognitive co-activation). Using accelerometry, we tested the effect of both interventions on tremor intensity and tremor variability. RESULTS: Levodopa significantly reduced tremor intensity (across behavioral contexts), while cognitive co-activation increased it (across treatment conditions). Crucially, the levodopa effect was significantly smaller during cognitive co-activation than during rest. Resting tremor variability increased after levodopa and decreased during cognitive co-activation. CONCLUSION: Cognitive stress reduces the levodopa effect on Parkinson's tremor. This effect may be explained by a stress-related depletion of dopamine in the basal ganglia motor circuit, by stress-related involvement of nondopaminergic mechanisms in tremor (e.g., noradrenaline), or both. Targeting these mechanisms may open new windows for treatment. Clinical tremor assessments under evoked cognitive stress (e.g., counting tasks) may avoid overestimation of treatment effects in real life.

Three Faces of Fragile X.

Fragile X syndrome (FXS) is the first of 3 syndromes identified as a health condition related to fragile X mental retardation (FMR1) gene dysfunction. The other 2 syndromes are fragile X-associated primary ovarian insufficiency syndrome (FXPOI) and fragile X-associated tremor/ataxia syndrome (FXTAS), which together are referred to as fragile X-associated disorders (FXDs). Collectively, this group comprises the 3 faces of fragile X. Even though the 3 conditions share a common genetic defect, each one is a separate health condition that results in a variety of body function impairments such as motor delay, musculoskeletal issues related to low muscle tone, coordination limitations, ataxia, tremor, undefined muscle aches and pains, and, for FXTAS, a late-onset neurodegeneration. Although each FXD condition may benefit from physical therapy intervention, available evidence as to the efficacy of intervention appropriate to FXDs is lacking. This perspective article will discuss the genetic basis of FMR1 gene dysfunction and describe health conditions related to this mutation, which have a range of expressions within a family. Physical therapy concerns and possible assessment and intervention strategies will be introduced. Understanding the intergenerational effect of the FMR1 mutation with potential life-span expression is a key component to identifying and treating the health conditions related to this specific genetic condition.

Sensory dynamic orthoses in mild to moderate upper limb tremor in multiple sclerosis: a mixed methods feasibility study.

OBJECTIVE: To explore the feasibility of conducting a Phase III randomized controlled trial evaluating sensory dynamic orthoses for upper limb tremor in multiple sclerosis. DESIGN: Mixed methods: double blind randomized placebo controlled pilot study and semi-structured interviews. SETTING: Rehabilitation centre. SUBJECTS: A total of 21 people with multiple sclerosis with upper limb tremor. INTERVENTIONS: Participants received a sensory dynamic orthosis sleeve or a non-compressive sleeve (placebo) that they wore eight hours a day, for nine weeks. MAIN MEASURES: Outcomes were completed at baseline and nine weeks. The primary outcome measure was the Fahn-Tolosa-Marin (FAHN) Tremor Rating Scale. Secondary outcome measures included the: Action Research Arm Test, Canadian Occupational Performance Measure, Psychological Impact of Assistive Device Scale and the Nine-hole Peg Test. RESULTS: Both sleeves were acceptable, although achieving a good fit was an issue. There were no significant between-group differences for the primary outcome measure. The median ± interquartile range change scores were 0.5 ±6.5 and 2 ±8 for the placebo and treatment group, respectively. The median ± interquartile range Canadian Occupational Performance Measure (performance subscale) demonstrated significant improvements ( p = 0.01) for the placebo group (1.1 ±1.65) compared with the treatment group (0 ±1.2). There was no between-group differences in the satisfaction subscale. The primary outcome measure was sensitive to detect change; however the Action Research Arm Test was not responsive in this study population. CONCLUSION: Undertaking an randomized controlled trial would be feasible and a minimum of 200 participants would be needed for a fully powered, definitive randomized controlled trial.

Research on musculoskeletal model of elbow joint for evaluating the feasibility of FES.

Tremor usually occurs in a patient's upper limb with a roughly sinusoidal profile. Understanding the inner mechanism of the involuntary movement is fundamental to improving tremor suppression treatments. Therefore, the musculoskeletal model of the elbow joint was developed in this study. Initially, healthy subjects were selected to simulate tremor and the tremulous data was collected with the purpose of sparing patients from fatigue. With the recorded joint angle and surface EMG (sEMG), the model was calibrated to subjects by optimization approach. The activation derived from the electric pulse was employed to drive the tuned model and the model's output was compared with the angle predicted by the EMG-driven musculoskeletal model. The results demonstrated that the performance of the calibrated model was improved by a smaller normalized root mean square error and a higher coefficient of determination compared with the no-tuned model. There was no significant difference between the angles estimated by the tuned model activated by the electric pulse and muscle excitation. It indicates that neural activation could be replaced by the electric pulse to excite the limbs for desired angle. Therefore, the study presents a good way to evaluate the feasibility of Functional Electric Stimulation to suppress tremor.

Online tremor suppression using electromyography and low-level electrical stimulation.

Tremor is one of the most prevalent movement disorders. There is a large proportion of patients (around 25%) in whom current treatments do not attain a significant tremor reduction. This paper proposes a tremor suppression strategy that detects tremor from the electromyographic signals of the muscles from which tremor originates and counteracts it by delivering electrical stimulation to the antagonist muscles in an out of phase manner. The detection was based on the iterative Hilbert transform and stimulation was delivered above the motor threshold (motor stimulation) and below the motor threshold (sensory stimulation). The system was tested on six patients with predominant wrist flexion/extension tremor (four with Parkinson disease and two with Essential tremor) and led to an average tremor reduction in the range of 46%-81% and 35%-48% across five patients when using the motor and sensory stimulation, respectively. In one patient, the system did not attenuate tremor. These results demonstrate that tremor attenuation might be achieved by delivering electrical stimulation below the motor threshold, preventing muscle fatigue and discomfort for the patients, which sets the basis for the development of an alternative treatment for tremor.

Improving mouse controlling and movement for people with Parkinson's disease and involuntary tremor using adaptive path smoothing technique via B-spline.

Many input devices are available for interacting with computers, but the computer mouse is still the most popular device for interaction. People who suffer from involuntary tremor have difficulty using the mouse in the normal way. The target participants of this research were individuals who suffer from Parkinson's disease. Tremor in limbs makes accurate mouse movements impossible or difficult without any assistive technologies to help. This study explores a new assistive technique-adaptive path smoothing via B-spline (APSS)-to enhance mouse controlling based on user's tremor level and type. APSS uses Mean filtering and B-spline to provide a smoothed mouse trajectory. Seven participants who have unwanted tremor evaluated APSS. Results show that APSS is very promising and greatly increases their control of the computer mouse. Result of user acceptance test also shows that user perceived APSS as easy to use. They also believe it to be a useful tool and intend to use it once it is available. Future studies could explore the possibility of integrating APSS with one assistive pointing technique, such as the Bubble cursor or the Sticky target technique, to provide an all in one solution for motor disabled users.

Tremor retrainment as therapeutic strategy in psychogenic (functional) tremor.

BACKGROUND: Entrainment, the change or elimination of tremor as patients perform a voluntary rhythmical movement by the unaffected limb, is a key diagnostic hallmark of psychogenic tremor. OBJECTIVE: To evaluate the feasibility of using entrainment as a bedside therapeutic strategy ('retrainment') in patients with psychogenic tremor. METHODS: Ten patients with psychogenic tremor (5 women, mean age, 53.6 ± 12.8 years; mean disease duration 4.3 ± 2.7 years) were asked to participate in a pilot proof-of-concept study aimed at "retraining" their tremor frequency. Retrainment was facilitated by tactile and auditory external cueing and real-time visual feedback on a computer screen. The primary outcome measure was the Tremor subscale of the Rating Scale for Psychogenic Movement Disorders. RESULTS: Tremor improved from 22.2 ± 13.39 to 4.3 ± 5.51 (p = 0.0019) at the end of retrainment. The benefits were maintained for at least 1 week and up to 6 months in 6 patients, with relapses occurring in 4 patients between 2 weeks and 6 months. Three subjects achieved tremor freedom. CONCLUSIONS: Tremor retrainment may be an effective short-term treatment strategy in psychogenic tremor. Although blinded evaluations are not feasible, future studies should examine the long-term benefits of tremor retrainment as adjunctive to psychotherapy or specialized physical therapy.

Active-assisted cycling improves tremor and bradykinesia in Parkinson's disease.

OBJECTIVES: To develop a rapid cadence cycling intervention (active-assisted cycling [AAC]) using a motorized bike and to examine physiological perimeters during these sessions in individuals with Parkinson's disease (PD). A secondary goal was to examine whether a single session of AAC at a high cadence would promote improvements in tremor and bradykinesia similar to the on medication state. DESIGN: Before-after pilot trial with cross-over. SETTING: University research laboratory. PARTICIPANTS: Individuals with idiopathic PD (N=10, age 45-74y) in Hoehn and Yahr stages 1 to 3. INTERVENTION: Forty minutes of AAC. MAIN OUTCOME MEASURES: Heart rate, pedaling power, and rating of perceived exertion were recorded before, during, and after a bout of AAC. Functional assessments included tremor score during resting, postural, and kinetic tremor. RESULTS: This AAC paradigm was well tolerated by individuals with PD without excessive fatigue, and most participants showed improvements in tremor and bradykinesia immediately after a single bout of cycling. CONCLUSIONS: This paradigm could be used to examine changes in motor function in individuals with PD after bouts of high-intensity exercise.

Resistance training can improve fine manual dexterity in essential tremor patients: a preliminary study.

OBJECTIVE: To determine if a short-term resistance training (RT) program of the upper limb can improve strength, fine manual dexterity, and quality of life in individuals with essential tremor (ET). DESIGN: Single group, dual pretest-posttest intervention study. SETTING: General community. PARTICIPANTS: Participants (N=6; mean age ± SD, 74±7y) clinically diagnosed as having ET (mean years diagnosed ± SD, 19±7y) were recruited into the study. INTERVENTION: A 6-week RT program involving unilateral dumbbell bicep curls, wrist flexion, and wrist extension exercises twice a week. MAIN OUTCOME MEASURES: Upper limb strength determined from five-repetition maximum; fine manual dexterity determined from the Purdue Pegboard Test (PPT) for the hand of the most affected limb, the hand of the least affected limb, both hands, and a bilateral assembly task; and quality of life determined from the Medical Outcomes Study 36-Item Short-Form Health Survey and the ET specific Quality of Life in Essential Tremor questionnaire. RESULTS: The RT program resulted in significant increases in 4 of the 6 upper limb strength measures. Significant improvements in the PPT were observed for the single hand components of this test. PPT performance improved immediately after RT when using the most affected limb, but these changes took longer to be observed for the least affected limb. CONCLUSIONS: Overall, fine manual dexterity improved in ET patients after a simple RT program. The findings of this preliminary study provide clear evidence that RT is worthy of further investigation as a therapy for improving functionality in ET patients.

Acute effects of passive leg cycling on upper extremity tremor and bradykinesia in Parkinson's disease.

BACKGROUND: Previous studies have shown that single bouts of high-rate active cycling (> 80 rpm) improve upper extremity motor function in individuals with Parkinson's disease (PD). It is unknown if passive leg cycling produces a similar effect on upper extremity function. This article examines whether passive leg cycling can promote immediate changes in upper tremor and bradykinesia in PD and if pedaling rates have variable effects. METHODS: Twenty individuals with mild-to-moderate idiopathic PD completed 4 sessions, with each session taking place 1 week apart. In the second to fourth sessions, a motorized bicycle was set to passively rotate the subjects' legs at rates of 60, 70, or 80 rpm for 30 minutes. Quantitative upper extremity motor assessments were completed immediately before and after each session. RESULTS: Passive leg cycling was shown to reduce tremor and bradykinesia in PD. However, the rate of passive cycling did not affect the degree of improvement in bradykinesia or tremor. CONCLUSION: These findings suggest that lower extremity passive cycling can promote changes in upper extremity motor function in individuals with PD.

Non-pharmacological and non-surgical interventions for tremor: a systematic review.

Tremor is a frequent disabling consequence of many neurological conditions. We performed a search of MEDLINE, CINAHL, EMBASE and the Cochrane Library to identify all primary research studies published up to November 2010 which investigated non-pharmacological and non-surgical treatments for tremor in humans. Neuromuscular physiotherapy, strength training and functional electrical stimulation show promise in their applicability and adaptability. Limb cooling may not be feasible for continuous management, but may be appropriate for specific tasks. Tremor-suppressing orthoses based on viscous materials, weighted splints and vibration therapies need further evaluation especially in the domiciliary setting and applied to improving personal activities of daily living. The evidence base for many rehabilitation interventions in tremor is poor. Future research should focus on high quality randomized controlled trials of non-pharmacological and non-surgical interventions which show promise.